Japan's whaling fleet is expected to begin soon its annual whale harvest in the Southern Ocean. Tokyo has yet to confirm when the ships involved in the controversial program will depart, or even where they will sail from. Some environmentalists groups say they are preparing to harass the whaling fleet. From Sydney, Phil Mercer reports the Australian government is calling for restraint.

Reports suggest that Japan's whaling fleet is preparing to leave port to commence its annual hunt in the Southern Ocean.

Details of the whalers' plans have not been made public, such are the sensitivities of the controversial expedition in the icy waters near Antarctica.

Tokyo has insisted that its whaling program is undertaken for scientific reasons and that the catch provides crucial data on the giant mammals.

Wildlife campaigners argue that such activities are meant to hide illegal commercial whaling, which was outlawed by the International Whaling Commission in 1986.

Environmental group Greenpeace, which has pursued the Japanese vessels in recent seasons, is keeping its ship at home this year, preferring instead to focus its campaigning efforts in Japan. However, the radical Sea Shepherd group is planning to again confront the whalers, forcing the Australian Government to call for restraint.

Greenpeace activist, Frode Pleym, believes that efforts to force Japan to abandon its annual hunt will be successful.

"It is a program which already is vulnerable and together with that the consumption is going down in Japan, the international pressure applied on Japan and now the tactics launched by Greenpeace to win the campaign in Japan, I feel very confident that we also in Japan will see an end to whaling and that whaling will be placed where it belongs, in the past," said Pleym.

Australia has lead international efforts to find diplomatic ways to force the Japanese to end its annual hunt.

Canberra has repeatedly called Japan's whaling activities an "unnecessary slaughter."

Fisheries officials in Tokyo have said that the fleet has set a target of 850 minke and 50 fin whales during this year's expedition in the Southern Ocean.

The World Wildlife Fund says seven of the 13 great whale species are classified as endangered or vulnerable, including the fin whales.

Last year, Japan retreated on a plan to hunt endangered humpback whales after international protests.